Confidence is generally seen as a good thing, if not in excess. Although overconfidence can hurt us, the bizarre health blog The Body Odd argues that it can also help us in the right situations. Here's how.

[I]f two parties want something, they can fight for it, which comes at a cost. If only one claims the prize, he gets it without a fight. If both parties are gifted with perfect judgment about each other's strength, then there'll never be a fight because the weaker party will know to back off. But contrary to what advocates of "rational markets" argue, there is almost always uncertainty. In that knowledge gap, you can talk yourself into thinking that your reach does not actually exceed your grasp. So deluded, you may try for what you want and sometimes the real stronger party won't compete. If you are, say, skinny, goofy, lisping Roger Rabbit, you can make a play for Jessica (va-va-voom!) and wind up with the sexiest babe in Toon Town.

Of course, it doesn't always work this way. You're bound for trouble if you're overconfident when the risk outweighs the reward. Overconfidence in your poker skills, for example, is the sort of thing that leaves many compulsive gamblers with empty pockets. The main thing to remember is this: be as confident as possible when you don't have much to lose. If you do, scale it back a bit.